Russia announced on Sept. 13 that it is expelling six staff members of the British Embassy in Moscow, accusing them of "espionage and subversive activities."
The step comes shortly after U.K. Foreign Secretary David Lammy's visit to Kyiv and amid rumors that the West may soon greenlight strikes with British long-range missiles against Russian soil.
Russia's Foreign Ministry said it had canceled the diplomats' accreditation based on "evidence" of their alleged intelligence activities provided by Russia's Federal Security Service (FSB).
London has not yet responded to Moscow's accusations. The U.K. has previously also expelled Russian diplomats over suspicions of espionage.
Moscow called the step a response to "numerous unfriendly steps by London" and said the diplomats' activity "threatened Russia's security." Russian pro-state media have often portrayed the U.K. as one of Russia's key geopolitical adversaries.
The FSB claimed it had uncovered "documentary materials... confirming London's coordination of the escalation of the international military-political situation."
The security service specifically named the British Foreign Office's Eastern Europe and Central Asia Directorate as the "lead unit coordinating the implementation of subversive policies" against Russia.
The FSB threatened further expulsions if more "evidence" of the supposed espionage was found.
The relations between London and Moscow have been marred by Russia's attempted poisoning of former Russian intelligence officer Sergei Skripal and his daughter on British soil in 2018 and by the U.K.'s extensive support for Ukraine.
Russia has been repeatedly accused of deploying spies to European capitals under the guise of diplomatic work. Dozens of embassy staff members have been expelled over the past years due to suspicions of espionage from Austria, Czechia, Moldova, Germany, and elsewhere.